It's never a stupid idea to try something new. It's how we learn, and you must start somewhere. Kudos to you.
I have a similar setup and run into this as well. A few years ago 250GB was ok but today not so much. If you are going to do a clean install, I'd consider obtaining at least a 1TB drive if you can for the OS.
Correct but if you have a full backup solution and image your drives daily, you can quickly revert to a good working condition in minutes if you mess up.
Again, it's not recommended to mess with the registry but we have to start somewhere if we are going to learn new things. Make sure to have a backup image of your drives.
Veeam has a nice free backup solution.
